Impulse relay



Sept. 13, 1966 c. A. SHERMAN IMPULSE RELAY Filed Dec. 11, 1963 INVENTOR. CIMRZES A. sum/-14 W ATTORNEYS United States Patent 3,273,024 IMPULSE RELAY Charles A. Sherman, Tacoma, Wash., assignors to Weyerhaeuser Company, Tacoma, Wash, a corporation of Washington Filed Dec. 11, 1963, Ser. No. 329,725 4 Claims. (Cl. 317157) This invention relates to electrical control apparatus and particularly, to an improved-impulse relay apparatus for actuating a control relay.

In electrically operated machines, which are cycled by an operator, it is desirable that the machine control apparatus be simple, inexpensive, reliable and durable. Whenever possible it is desirable to cycle the machine by pushing one button which, when pushed, will actuate the electrical controls to one operating condition which condition will be maintained until the button is again pushed. Such a control is termed an impulse relay.

In the past, impulse relays have been used which are of mechanical construction; however, such relays have not provided satisfactory service over extended periods of usage. Often the mechanical parts of the relays become unreliable after repeated use due to dirt, wear and breakage.

It is a principal object of this invention to provide an impulse relay which is not adversely vaffected by dirt and prolonged usage.

It is a further object of this invention to provide an electrical impulse relay which is made up of simple, inexpensive, electrical components which are reliable and effective in continuous operation.

In the practice of this invention I provide an impulse relay which comprises; a capacitor which is alternatively charged positively and negatively, a .pair of diode rectifiers which are alternatively connected to the capacitor, 9. reed switch which is opened or closed by changes in direction of current flow through a coil surrounding the reed switch and which is held closed by the magnetic force of a permanent magnet which is placed in the vicinity of the reed switch, a relay which changes the connection between the capacitor and the rectifiers and which is energized by the closing of the reed switch, and a pulse switch which when closed makes contact between the capacitor and the reed coil to discharge the capacitor through the reed coil.

Also in the practice of the invention I provide a reed switch which is open in the normal condition, which is biased to an open or closed position by the magnetic force caused by the direction of current flow through a coil surrounding the reed switch, and which is held in the closed position by the magnetic force of another magnet which is of a magnitude sufiicient to hold the reed switch closed but insufiicient to actuate the switch from an open to a closed condition.

How the foregoing objects, together with such other objects as may appear hereafter or are incident to my invention are attained, is illustrated in the preferred form in the accompanying drawing. Various changes may be made, however, in the construction and arrangements of parts in the apparatus and certain features may be used without the use of other features. All such modifications are intended to be within the scope of the appended claims.

The figure shows a schematic diagram of the control circuit of the impulse relay apparatus.

In detail, the figure shows an impulse relay 1 which actuates a control relay 3 which is shown within the dashed lines. The control relay 3 is connected by means of negative relay lead 5 to negative charging diode rectifier 7, and likewise, control relay 3 is connected by means of positive relay lead 9 to positive charging diode rectifier 11. The specific polarity of the diode rectifiers 7 and 11 is given by way of example only and of course is dependent upon the direction of wrapping of the wires in the coil 33 and the polarity of the permanent magnet 49. Rectifiers 7 and 11 have a common connection at junction 12 with rectifier lead 13 which includes resistor R1 and is connected to junction 15. From junction 15, capacitor lead 17 which includes capacitor 19 is connected to junction 21. Also from junction 15, switch lead 23 which includes resistor R2 and pulse switch 25 is connected to junction 27. Between junctions 21 and 27 is lead 29 which includes resistor R3.

Continuing past junction 27 is first coil lead 31 which is connected to reed coil 33. A second coil lead 35 connects reed coil 33 at junction 37 with lead 39 which at the other end is connected to junction 21. Also joined at junction 37 is first alternating current power lead 43 and first reed contact 45. The first reed contact 45 is at one end of reed switch 47 which as shown is glass enclosed. Above the reed switch 47 is permanent magnet 49 which has suflicient magnetic strength to hold first reed contact 45 in physical contact with second reed contact 51, once physical contact between the two reed contacts 45 and 51 has been made by the energization of the reed coil 33. The permanent magnet 49 does not have sufficient strength however to pull contacts 45 and 51 together when reed coil 33 is not energized. It should be noted that reed switch 47 is a normally open switch. Although the magnet 49 is shown as a permanent magnet it is possible to use an electric magnet in its place if it has a constant direction and magnitude of current flow through it.

The second reed switch contact 51 is connected to the control relay coil 53 in control relay 3. The other end of the control relay coil 53 is connected at junction 55 with the second alternating current power lead 57. Energizing relay coil 53 causes the relay yoke 59 to move from the normal right-hand position to the energized left-hand position. Attached to the control relay yoke 59 is left switch arm 61 which is connected by means of power lead 63 to junction 55. Also attached to control relay yoke 59 is right switch arm 65 which is connected electrically to the apparatus being controlled by the control relay 3. In the normal condition of the control relay coil 3, the right switch arm 65 makes contact with the normal control contact 67, and in the energized condition of the control relay 3, the right switch arm 65 makes contact with the energized control con-tact 69. Similarly left switch arm 61 makes contact with negative relay lead 5 in the normal condition and makes contact with positive relay lead 9 in the energized condition.

OPERATION The control relay 3 is connected to diode rectifiers 7 and 11 in the manner shown to charge the capacitor 19 either positively or negatively, depending upon the position of the left switch arm 61. The resistor R1 is placed in the circuit between the diode rectifiers 7 and 11 and the capacitor 19 to limit the charging current of the capacitor 19 and to eliminate surge currents, The resistor RZ serves to prolong the discharge of the capacitor 19 through the reed coil 33. The resistor R3 stabilizes the reed switch circuit.

The control relay coil 53 is energized or de-energized by the closing or opening of the reed switch contacts 45 and 51. In the vicinity of the reed switch 47 is the magnet 49, having suflicien-t strength to bias or hold the contacts 45 and 51 closed, but insufiicient strength to cause the closure of the contacts 45 and 51.

With the impulse relay 1 in the condition shown in the figure, the negative diode rectifier 7 is connected to the capacitor 19 and impresses a negative charge on the capacitor 19. Once the pulse switch 25 is closed the capacitor 19 discharges through the reed coil 33 causing the reed switch contacts 45 and 51 to close. The pulse switch 2 can then be released without effect since the magnetic field of the magnet 49 is sulficiently strong to hold the contacts 45 and 51 together. Since the reed switch 47 is closed the control relay coil 53 is energized pulling yoke 59 and left switch arm 61 to the left-hand position to connect positive diode rectifier 11 with capacitor 19 impressing a positive charge on the capacitor 19. Whenever the pulse switch 25 is again closed the positively charged capacitor 19 discharges through the reed coil 33 causing an opposing magnetic field to that of the magnet 49 which in turn breaks the connection between the reed switch contacts 45 and 51 de-energizing the control relay coil 53 returning the control relay 3 to the normal condition.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. An impulse relay apparatus which comprises in combination:

capacitor means,

first means for charging said capacitor means with a charge of one polarity,

second means for charging said capacitor means with a charge of a polarity opposite to said one polarity, first switch means having an opened and a closed condi-tion,

holding means for holding said first switch in said closed condition,

coil means for biasing said first switch means to said closed position responsive to current flow through said coil means of a first direction and for opposing the force of said holding means for biasing said first switch means to said open position responsive to current flow through said coil means of a direction opposite to said first direction,

relay means responsive to said conditions of said first switch means for switching contact between. said capacitor means and said first charging means and between said capacitor means and said second charging means,

second switch means for connecting said coil means to said capacitor means whereby said capacitor means discharges said charges through said coil means to actuate said first switch means to either of said conditions.

2. The appanatus of claim 1 wherein said first switch means is a reed switch.

3. The apparatus of claim 1 wherein said holding means is a permanent magnet having sufficient strength to hold said first switch means in said closed condition but having insufiicient strength to bias said first switch means from said open condition to said closed condition.

4. The apparatus of claim 1 wherein said first and said second charging means include diodes and a power source.

References Cited by the Examiner UNITED STATES PATENTS 2,789,256 4/1957 Stenerson 317-l39 3,002,067 9/ 1961 Baldwin 317--123 OTHER REFERENCES Hovgaard: Development of Reed Switches and Relays, Bell System Technical Journal, vol. 34, March 1955, pp. 326-328.

MILTON O. HIRSHFIELD, Primary Examiner.

SAMUEL BERNSTEIN, Examiner. J. A. SILVERMAN, Assistant Examiner. 

1. AN IMPULSE RELAY APPARATUS WHICH COMPRISES IN COMBINATION: CAPACITOR MEANS, FIRST MEANS FOR CHANGING SAID CAPACITOR MEANS WITH A CHARGE OF ONE POLARITY, SECOND MMEANS FOR CHARGING SAID CAPACITOR MEANS WITH A CHARGE OF A POLARITY OPPOSITE TO SAID ONE POLARITY, FIRST SWITCH MEANS HAVING AN OPENED AND A CLOSED CONDITION, HOLDING MEANS FOR HOLDING SAID FIRST SWITCH IN SAID CLOSED CONDITION, COIL MEANS FOR BIASING SAID FIRST SWITCH IN SAID CLOSED POSITION RESPONSIVE TO CURRENT FLOW THROUGH SAID COIL MEANS OF A FIRST DIRECTION AND FOR OPPOSING THE FORCE OF SAID HOLDING MEANS FIR BIASING SAID FIRST SWITCH MEANS TO SAID OPEN POSITION RESPONSIVE TO CURRENT FLOW THROUGH SAID COIL MEANS OF A DIRECTION OPPOSITE TO SAID FIRST DIRECTION, RELAY MEANS RESPONSIVE TO SAID CONDITIONS OF SAID FIRST SWITCH MEANS FOR SWITCHING CONTACT BETWEEN SAID CAPACITOR MEANS AND SAID FIRST CHARGING MEANS AND BETWEEN SAID CAPACITOR MEANS AND SAID SECOND CHARGING MEANS, SECOND SWITCH MEANS FOR CONNECTING SAID COIL MEANS TO SAID CAPACITOR MEANS FOR CONNECTING SAID COIL MEANS MEANS DISCHARGES SAID CHARGES THROUGH SAID COIL MEANS TO ACTUATE SAID FIRST SWITCH MEANS TO EITHER OF SAID CONDITIONS. 